<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
<!--内部样式-->
  <style>
    h1{
      color: green;
    }
  </style>
  <link rel="stylesheet" href="style.css">
</head>
<body>
<!--行内样式：在标签元素中编写style属性-->
<h1 style="color:red;">标题</h1>
</body>
</html>